用戶的兩臺nexus5548已經使用很多年了，系統版本是5.2.1，一些高級功能在5.2.1中不被支持。因業務需要，需要對這兩臺5548進行升級，查看文檔，得知要將當前版本升級到7.3.5不能一步到位。
爲了保證升級的穩定，我制定的升級步驟是先升到6.0.2.N2.7，然後再升級到7.1.4.N1.1，最後再升級到7.3.5。
準備工作：
1、準備相應版本的NX-OS
2、在本機搭建一臺FTP服務器。
下面升級馬上開始：
升級前做好配置文件的備份，事實證明，這樣做是對的！
1、通過命令將系統文件上傳到N5548中，命令如下：
5548_A# copy ftp://10.96.1.240/n5000-uk9-kickstart.6.0.2.N2.7.bin bootflash:
5548_A# copy ftp://10.96.1.240/n5000-uk9.6.0.2.N2.7.bin bootflash:
在這裏我沒有一次性將所有的文件都上傳上去，因爲空間不夠，所以升一個版本上傳一個版本。
2、安裝升級
用戶的環境中是兩臺5548做的HSRP，在這裏我先升級的Active
5548_A# install all kickstart bootflash:n5000-uk9-kickstart.6.0.2.N2.7.bin system bootflash:n5000-uk9.6.0.2.N2.7.bin
Verifying image bootflash:/n5000-uk9-kickstart.6.0.2.N2.7.bin for boot variable "kickstart".
[####################] 100% -- SUCCESS
Verifying image bootflash:/n5000-uk9.6.0.2.N2.7.bin for boot variable "system".
[####################] 100% -- SUCCESS
Verifying image type.
[####################] 100% -- SUCCESS
Extracting "system" version from image bootflash:/n5000-uk9.6.0.2.N2.7.bin.
[####################] 100% -- SUCCESS
Extracting "kickstart" version from image bootflash:/n5000-uk9-kickstart.6.0.2.N2.7.bin.
[####################] 100% -- SUCCESS
Extracting "bios" version from image bootflash:/n5000-uk9.6.0.2.N2.7.bin.
[####################] 100% -- SUCCESS
Performing module support checks.
[####################] 100% -- SUCCESS
Notifying services about system upgrade.
[####################] 100% -- SUCCESS
Compatibility check is done:
Module bootable Impact Install-type Reason
------ -------- -------------- ------------ ------
1 yes disruptive reset Non-disruptive install not supported if L3 was enabled
Images will be upgraded according to following table:
Module Image Running-Version New-Version Upg-Required
------ ---------- ---------------------- ---------------------- ------------
1 system 5.2(1)N1(4) 6.0(2)N2(7) yes
1 kickstart 5.2(1)N1(4) 6.0(2)N2(7) yes
1 bios v3.6.0(05/09/2012) v3.6.0(05/09/2012) no
1 SFP-uC v1.0.0.0 v1.0.0.0 no
1 power-seq v1.0 v3.0 yes
3 power-seq v5.0 v5.0 no
1 uC v1.2.0.1 v1.2.0.1 no
Switch will be reloaded for disruptive upgrade.
Do you want to continue with the installation (y/n)? [n] y
Install is in progress, please wait.
Performing runtime checks.
[####################] 100% -- SUCCESS
Setting boot variables.
[####################] 100% -- SUCCESS
Performing configuration copy.
[####################] 100% -- SUCCESS
Module 1: Refreshing compact flash and upgrading bios/loader/bootrom/power-seq.
Warning: please do not remove or power off the module at this time.
Note: Power-seq upgrade needs a power-cycle to take into effect.
Use command 'reload power-cycle'
Note: Micro-controller upgrade needs a power-cycle to take into effect.
On success of micro-controller upgrade, SWITCH OFF THE POWER to the system and then, power it up.
[####################] 100% -- SUCCESS
Finishing the upgrade, switch will reboot in 10 seconds.
待系統重啓後升級完成。按照同樣的方法對standby進行升級。6.0.2.N2升級完成之後，系統沒有問題，各應用也正常。
下面接着升級。
在這裏我只截取部分內容：
Images will be upgraded according to following table:
Module Image Running-Version New-Version Upg-Required
------ ---------------- ---------------------- ---------------------- ------------
1 system 6.0(2)N2(7) 7.1(4)N1(1) yes
1 kickstart 6.0(2)N2(7) 7.1(4)N1(1) yes
1 bios v3.6.0(05/09/2012) v3.6.0(05/09/2012) no
1 power-seq v3.0 v3.0 no
1 SFP-uC v1.0.0.0 v1.0.0.0 no
3 power-seq v5.0 v5.0 no
1 microcontroller v1.2.0.1 v1.2.0.1 no
不知道爲什麼，在我升級到7.1.4的時候出了點狀況，配置文件中關於FC的部分配置丟失了！！還好事前備份了配置文件，迅速修改配置後，系統恢復。
Images will be upgraded according to following table:
Module Image Running-Version New-Version Upg-Required
------ ---------------- ---------------------- ---------------------- ------------
1 system 7.1(4)N1(1) 7.3(5)N1(1) yes
1 kickstart 7.1(4)N1(1) 7.3(5)N1(1) yes
1 bios v3.6.0(05/09/2012) v3.6.0(05/09/2012) no
1 power-seq v3.0 v3.0 no
1 SFP-uC v1.0.0.0 v1.0.0.0 no
3 power-seq v5.0 v5.0 no
1 microcontroller v1.2.0.1 v1.2.0.1 no
最後從7.1升級到7.3，升級完成後配置文件沒有丟失，系統正常！整個升級過程雖然出了點小插曲，不過還算正常。